Shielded wire stripper



Oct. 20, 1964 R. c. HAVENS SHIELDED WIRE STRIPPER 2 Sheets-Sheet 1 m T- W 5 M M C. X h

Filed May 24, 1962 Oct. 20, 1964 R. c. HAVENS 3,153,358

SHIELDED WIRE STRIPPER Filed May 24, 1962 2 Sheets-Sheet 2 28 FIG. 4 I7 30 27 liiin:

FIG-6 INVEN TOR. REX c. HA l/ENS M a i United States Patent 3,153,358 SHIELDED WIRE STRIPPER Rex C. Havens, 2235 Bahia Drive, La Jolla, Calif. Filed May 24, 1962, Ser. No. 197,542 3 Claims. (Cl. 81--9.51)

The present invention relates to a wire stripper and more particularly to a wire stripper for stripping braided wire from around a cable and specifically to a wire stripper for Stripping wire braid from around one end of a shielded cable.

The prior art shielded wire strippers have encountered two major problems, the first being a method of pushing the shield away from the end to be stripped and the other being the provision of a positive shearing action.

According to the invention, first and second dies or blocks are provided having bores in axial alignment. The cable to be stripped is passed through the two bores. The first bore has a protruding annular extension around it and the second bore has an annular recess surrounding it which mates with the annular extension of the first bore. Means are provided for moving the second bore toward the first bore or vice versa, and further means are provided for moving at least one pin radially in one of the blocks toward the cable upon relative movement of the two bores for gripping the shield and bunching the shield between the two blocks. As the two blocks come together, the protrusion surrounding one bore moves into the recess surrounding the second bore and the bunched portion of the shield is sheared. The cable can then be removed leaving a portion of the shield cleanly cut away from the inner par-ts of the cable. Thus, the disadvantages or problems of the prior art are obviated in that there is positive gripping action of the shield for bunching the shield without rupturing the inner insulation of the conductor and the shield is sheared evenly and completely at the desired point.

Thus, it is an object of the present invention to provide an improved shielded wire stripper for removing a portion of braided shield around a conductor.

Another object of the present invention is to provide a shielded wire stripper which has a positive gripping action of the shield without rupturing other insulative parts of the wire to be stripped.

A further object of the present invention is the provision of a shielded wire stripper which has a positive shearing action.

Yet another object of the present invention is to provide a shielded wire stripper which is simple, versatile, economical to construct and requires little or no adjustment or maintenance.

Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings in which like reference numerals designate like parts throughout the figures thereof and wherein:

FIG. 1 is a plan view of a preferred form of the app-aratus in accordance with the invention;

FIGS. 2, 3, 4 and 5 are views similar to FIG. 1 but showing the apparatus in several stages of its operating cycle, and

FIG. 6 is a view taken along the line 6-6 of FIG 1.

Referring now to FIG. 1 there is shown cable 11 having outer insulation 12 and sheath or braid 13. Cable 11 is housed in bore 16 and counter-bore 14 of block 17. The shielded portion 13 of cable 11 also passes through bore 19 and counter-bore 18 of block 21. Block 21 has shoulder 22 abutting face 23 of block 24. Block 21 is housed within bore 26 of block 24. Bore 27 in 3,153,358 Patented Oct. 2Q, 1964 block 21 receives pin 28. Block 17 has an annular protruding section 29 of substantially the same diameter as bore 18. Shoulder 31 abuts face 32 of block 33, block 33 has a bore 34 which houses block 17. Cam 36 is mounted on block 33 with an indented shoulder 37 which abuts ball 38 within bore 39 in block 24. Ball 38 abuts head 41 of pin 28, spring 42 is captured between shoulder 43 of head 41 and shoulder 44 of bore 39.

Since FIGS. 2, 3, 4 and 5 is the same view of the apparatus as FIG. 1 and has identical par-ts but merely shows them in different stages of the operational cycle a parts list with reference to these figures is deemed unnecessary.

A sectional view of FIG. 1 taken along lines 66 is shown at FIG. 6. As cams 36 are advanced along block 24 balls 38 are forced radially toward cable 11. This in turn forces pins 28 radially also toward cable 11. Pins 28 have ends 45 which are grooved to grip sheath 13 of cable 11 when cam 36 forces ball 38 radially toward cable 11.

' Operation Referring back to FIG. 1 cable 11 is first stripped of outer insulation 13 back to point 46, this exposes shield 13 and the entire cable assembly is placed into bore 14 of bushing 17 and the exposed sheath portion 13 will then fit through bore 16 of bushing 17, and bore 19 and counter-bore 18 of bushing 21. At this point assembly 24 is moved axially to the left or toward assembly 33. This causes cam 36 to engage ball 38 in bore 39 of -as sembly 24 at shoulder 37, forcing the bail downward against head 41 of pin 28. Spring 42 abuts face 43 of head 41 and the end face of shoulder 44 and bore 39, which biases pin 28 away from shield 13. The action of cam 36 thus forces ball 38 and pin 28 further down into bore 39 and counter-bore 30 of assembly 24 and bore 27 of bushing 21 until surface 45 of pin 28 grips shield 13 of cable 11. Ideally bores 16 and 19 snugly and frictionally engage the cable to prevent slippage when there is relative movement of the blocks. Should the cable be of a diameter slightly too small for this snug and frictional fit, however, the device will operate satisfactorily as long as pin 23 engages shield 13 and the entire cable assembly is caused to move or stay with the block 33. This can be effected by crimping the cable against block 33 by hand as the machine is operated.

Referring to FIG. 2 as assembly 24 is moved closer to assembly 33 the shielding 13 is bunched at 48 since it will slide back over conductors 51 due to the gripping action of grooved surface 45 of pin 28. In FIG. 3, shoulder 29 of bushing 17 is moved into counter-bore 18 of bushing 21 shearing off shielding 13 at 49 leaving bunched up portion 48. Upon the resumption of the original position of assembly 24 with respect to assembly 33, as shown in FIG. 4, the shielding 13 has been broken cleanly and sharply at 49, and the portion to the right is loose around cable 51.

At FIG. 5 the cable 11 has been removed entirely from the assembly leaving conductors 51 exposed and a sharp trim at 49 of shielding 13. The cut oif portion of shielding 13 shown at 52 can easily be removed when cam 36 has allowed pin 28 to release its grip on the shielding and the pinched severed portion 48 also can be removed with relative ease.

It should be understood of course, that the foregoing disclosure relates to only a preferred embodiment of the invention and that it is intended to cover all changes and modifications of the example of the invention herein chosen for the purposes of the disclosure which do not constitute departures from the spirit and scope of the invention, for example, bushings 17 and 21 could be integral with blocks 33 and 24 but it has been found that for convenience of construction the bushing type of construction or assembly is preferable. Also this allows the same assembly to accommodate different size cables by merely replacing the bushings with bushings having axial bores of a diiferent diameter. Cam 36 could also be integral with block 33 as shown in FIG. 6 cams 36 could be one cylindrical encasement around blocks 33 and 24. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

What is claimed is:

1. A shielded cable stripper for removing a portion of 'wire shield from the end of a cable comprising first and second blocks having first and second axially aligned bores,'respectively, an annular recess surrounding said first bore, an annular extension surrounding said second bore, said first block having a plurality of radial bores, pin means inserted in said radial bores, cam means carried by said second block, said cam means having an inside dimension substantially equal to said first blocks outside dimension, engaging means abutting said pin means and said cam means when engaged by said cam means for moving said pin means radially toward said axially aligned bore, whereby upon inserting a shielded cable of substantially the same diameter as said axially aligned bores through said bores and moving said first block and said second block toward each other, said References Qited by the Examiner UNITED STATES PATENTS 1,491,229 4/24 Goldsmith 81-951 2,395,534 2/46 Cook 279-82 2,929,285 3/60 Gulemi 8 1-9.51 2,988,940 6/61 Folkenroth et al 81-951 3,044,333 7/62 Broske 81-9.51 3,085,455 4/63 Hurlbut et al 819.51 3,089,367 5/63 SC'hluter 81-951 3,139,778 7/ 64 Bielinski et al. 81-951 J FOREIGN PATENTS 609,834 10/48 Great Britain.

WILLIAM FELDMAN, Primary Examiner. 

1. A SHIELDED CABLE STRIPPER FOR REMOVING A PORTION OF WIRE SHIELD FROM THE END OF A CABLE COMPRISING FIRST AND SECOND BLOCKS HAVING FIRST AND SECOND AXIALLY ALIGNED BORES, RESPECTIVELY, AN ANNULAR RECESS SURROUNDING SAID FIRST BORE, AN ANNULAR EXTENSION SURROUNDING SAID SECOND BORE, SAID FIRST BLOCK HAVING A PLURALITY OF RADIAL BORES, PIN MEANS INSERTED IN SAID RADIAL BORES, CAM MEANS CARRIED BY SAID SECOND BLOCK, SAID CAM MEANS HAVING AN INSIDE DIMENSION SUBSTANTIALLY EQUAL TO SAID FIRST BLOCK''S OUTSIDE DIMENSION, ENGAGING MEANS ABUTTING SAID PIN MEANS AND SAID CAM MEANS WHEN ENGAGED BY SAID CAM MEANS FOR MOVING SAID PIN MEANS RADIALLY TOWARD SAID AXIALLY ALIGNED BORE, WHEREBY UPON INSERTING A SHIELDED CABLE OF SUBSTANTIALLY THE SAME DIAMETER AS SAID AXIALLY ALIGNED BORES THROUGH SAID BORES AND MOVING SAID FIRST 